The Digital Video Broadcasting-Terrestrial standard (DVB-T) utilises Orthogonal Frequency Division Multiplexing (OFDM) to communicate data representing video images and sound to receivers via a broadcast radio communications signal. There are known to be two modes for the DVB-T standard which are known as the 2k and the 8k mode. The 2k mode provides 2048 sub-carriers whereas the 8k mode provides 8192 sub-carriers. Similarly for the Digital Video Broadcasting-Handheld standard (DVB-H) a 4k mode has been provided, in which the number of data carriers is three thousand and twenty four.
In accordance with a further development of the Digital Video Broadcasting-Terrestrial broadcasting standard, known as DVB-T2, there has been proposed that further modes for communicating data be provided in order to increase a data rate that can be provided by a digital broadcast system. This is for example to allow the DVB-T2 standard to be used to carry High Definition television signals.
In order to improve the integrity of communicated data, it has been proposed to utilise a space-frequency block coding technique known as Alamouti encoding, which requires that data symbols be paired, encoded and transmitted as pairs of modulation symbols. As such, in combination with an OFDM modulation system a Multiple-In-Multiple-Out (MIMO) or Multiple-In Single-Out (MISO) communications system can be formed.
European patent EP1617569 discloses a MIMO communications system, which utilises OFDM.